Leong, K.M., A. Ortolani, L.H. Graham, and A. Savage (2003). The use of low-frequency vocalizations in African elephant (Loxodonta africana) reproductive strategies.Hormones and Behavior 43(4): 433-43.NAL Call Number: QP801.H7H64Abstract: Fertility-advertisement calls in females are predicted to occur in nonmonogamous species where males and females are widely separated in space. In African elephants, low-frequency vocalizations have thus been suggested as a reproductive strategy used by fertile females to attract mates. This study examined the use of low-frequency vocalizations with respect to different phases of the estrous cycle in African elephants by simultaneously monitoring vocalizations, behavior, and hormonal profiles. Subjects were one male and six female African elephants housed at Disney's Animal Kingdom. No acoustically distinct vocalizations were restricted to the ovulatory follicular phase. However, overall rate of low-frequency vocalization as well as the rate of one acoustically distinct vocalization changed over the estrous cycle, with highest rates of calling related to the first period of follicular growth, or anovulatory follicular phase. Elevated rates of vocalization thus were not restricted to behavioral estrus and occurred much earlier in the estrous cycle than in most species that produce fertility-advertisement calls. Both herd composition and elephant identity also affected rates of vocalization. Vocalizations therefore may not be reliable signals of actual fertility. However, the increase in vocalizations in advance of estrus may attract males to the herd prior to ovulation, facilitating both male-male competition and female choice. Once present in the herd, males may then switch strategies to use more reliable chemical and visual cues to detect ovulating females.Descriptors: physiology, sex behavior, animal physiology, vocalization, estrous cycle physiology, luteinizing hormone blood, ovulation physiology, reproduction physiology, social behavior.

O' Connell Rodwell, C.E., J.D. Wood, T.C. Rodwell, S. Puria, S.R. Partan, R. Keefe, D. Shriver, B.T. Arnason, and L.A. Hart (2006). Wild elephant (Loxodonta africana) breeding herds respond to artificially transmitted seismic stimuli.Behavioral Ecology and Sciobiology 59(6): 842-850. ISSN: 0340-5443.Online:http://dx.doi.org/10.1007/s00265-005-0136-2NAL Call Number: QL751.B4Abstract: Seismic communication is known to be utilized in insects, amphibians, reptiles, and small mammals, but its use has not yet been documented in large mammals. Elephants produce low-frequency vocalizations, and these vocalizations have seismic components that propagate in the ground, but it has not yet been demonstrated that elephants can detect or interpret these seismic signals. In this study, we played back seismic replicates of elephant alarm vocalizations to herds of wild African elephants in their natural environment and observed significant behavioral changes indicating that they had detected these signals. Seismic communication may provide an important complement to existing communication modes used by elephants. Seismic sensitivity may also provide elephants with an additional modality for sensing important environmental cues such as changes in weather patterns or seismic disturbances.Descriptors: African elephant, Loxodonta africana, Elephant seismic communication, seismic stimuli, replicas, elephant alarm vocalizations.